Coat an 11x7" baking dish with nonstick spray.,Coat a small nonstick skillet with nonstick spray and warm over medium heat.,Add the sausage and cook, stirring to break it up, until crumbly and no longer pink.,______,Cut the bread into 1/2" cubes.,Place half of the bread cubes in the prepared baking dish.,Top with 3/4 Celsius of the cheese.,Top with the remaining bread cubes and the sausage.,Sprinkle the remaining 3/4 Celsius cheese evenly over top.,In a medium bowl, beat together the egg whites, evaporated milk, 1% milk, mustard powder, and salt.,Pour over the bread, cover, and refrigerate overnight.,Preheat the oven to 350*.,Uncover and bake for 45 minutes, or until golden and puffy.,Serve immediately.